I have a website thats been running Umbraco 7 with Contour forms for years without a captcha which has now suddenly started to receive a lot of spam emails coming through. I think the built in captcha into Contour forms is no longer supported.

After googling there are a few threads on it but i dont think it would work as this site is not using MVC.

Is there a solution/steps i could take to add a captcha to these contour forms especially when using webforms/masterpages?